I am an operations director for a church. Our church building was built in 1986 and expanded in 1995. Originally there were small a/c units for the building, but after the expansion two 30 ton split gas furnace units were installed in 1991. My question is they are on 24/7, they are trane units, had no real problems, have regular maintenance. Our PNA states their useful life is 15-20 years. Our finance council is concerned that they may go before that time and has asked us to get bids. Can anyone tell me the useful life of these units, as this would be a huge expense for our parishioners is not necessary. Because of the age, I've been told we cannot change to programmable thermostats this was the opinion of the vendors.

What is the overall condition of the condensers and compressors and the evap coils etc. Are the furnace heat exchangers still in good shape? You cannot really put an age limit on equipment as long as it is maintained well. If however the equip. is run down and breaking down continuously then there are issues. If you are using programmable t-stats why are they on 24/7? Surely you can program downtime into the stats right? Anyways fill us in please.